Method and apparatus for charging a blast furnace



J. B. HAZLE PAID. 11, 1958 METHOD AND APPARATUS FOR CHARGING A BLAST FURNACE Filed Aug. 4, 1953 2 Sheets$heet 1 INVENTbR. JE/YAQB. hkZAf BY k/ ae J. B. HAZLE Feb. 11, 1958 METHOD AND APPARATUS FOR CHARGING A BLAST FURNACE Filed Aug. 4, 1953 2 Sheets-sheaf, 2

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flrroplveys United States Patent METHOD AND APPARATUS FOR CHARGING A BLAST FURNACE John B. Hazle, Shaker Heights, Ohio, assignor to Interlake -Iron Corporation, Cleveland, Ohio, a corporation of This invention relates to blast furnaces and particularly to a method and apparatus for charging the furnace.

One method heretofore employed for charging a blast furnace has included the step of rotating the small bell hopper during the dumping operation of a skip car and maintaining a hopper speed which is suflicient to achieve at least one revolution during the dumping of the skip load. The materials charged into the furnace require different lengths of time for effecting a dumping operation from a skip car, hence, the hopper is rotated at a speed which would cause the hopper to make at least one revolution during the time required for the fastest dumping operation of any of the materials to be fed into the furnace.

I have found that where two skip cars are provided, one of which deposits its load on one side of the hopper, and the other of which deposits its load on the other side of the hopper, there is an advantage in imparting a swirl to the material as it enters the bell hopper. This can be accomplished in a satisfactory manner by utilizing a conical receiving hopper, but I have found that when the material enters the bell hopper in a direction generally opposed to that of rotation, the combined action of the swirling motion imparted to the material by the receiving hopper and the rotating motion of the bell hopper is such that more uniform distribution is provided when the material enters the bell hopper in a direction which is generally opposed to that of rotation of the bell hopper.

. An object of the present invention is to retain the marked advantages of uniformity of distribution incident to the rotation of the hopper, in the manner stated aforesaid, -and yet to assure substantial equality in uniformity of distribution where two skip cars are utilized for conveying the charging materials to the furnace.

My invention may be carried out in more than one manner, the preferred manner being to reverse the direction of rotation during successive durnpings of the skip cars so that the material flowing from each car enters the hopper with a swirling motion in a direction which is generally opposed to the direction of rotation of the hopper. Thus for every dumping operation of skip car No. l, the hopper would be rotated for example in a clockwise direction, and for every dumping operation of skip car No. 2, the hopper would be rotated in a counter-clockwise direction.

A modification of my invention includes an arrangement of guides in one-half of the receiving hopper, whereby the direction of rotation of the hopper need not be altered but instead the direction of flow of the materials in the receiving hopper is changed by the guides so as to cause the material to enter the rotating hopper in a direction which is generally opposite to the direction of rotation thereof.

The manner in which the invention is carried out is illus trated in the drawings, wherein Fig. 1 is a vertical section partly in side elevation of a furnace top and charging mechanism to which the present invention may be applied; Fig.2 is a top plan view of the skip car tracks and of the receiving hopper into which the skip cars dump their loads; Fig. '3 is a'vertical section taken on a scale larger than that of Fig. l' and showing a driving mechanism for the upper 2,822,936 Patented Feb. 11 1958 or small bell hopper; Fig. 4 is a top plan view of a double skip track with a modified construction of receiving hopper; Fig. 5 is a vertical section taken through the receiving hopper of Fig. 4 on a plane indicated by the line 55;and Fig. 6 is a wiring diagram showing a suitable electric circuit arrangement for operating the apparatus in accordance with the disclosure of Figs. 1 and 2.

Referring to Fig. l, the dome of the blast furnace body is indicated at 10, at the top of which, is shown a small bell 11 and a large bell 12 arranged in series with one another. The small bell is attached to the lower end of a tube 15 which is adapted to be raised and lowered by a hoisting mechanism (not shown) for raising and lowering the bell with respect to a small bell hopper 20; The large bell is attached to the lower end of a rod 21 which passes through the tube 15, and which is adapted to be raised and lowered by suitable hoisting mechanism (not completely shown), whereby the large bell is adapted to be raised and lowered with respect to a large bell hopper 25. Thus, the small bell normally holds the bottom of the hopper 20 closed, while the large bell normally holds the bottom of the hopper 25 closed.

Disposed above the hopper 20 is a funnel-shaped receiving hopper 30 into which the contents of a skip car, indicated by the broken lines 31, may be dumped when the car reaches the top of its inclined trackway. In Fig. 2, I have shown two sets of skip car tracks one being designated 32 and the other being designated 33. 'Additionally, I have shown the receiving hopper as being substantially rectangular in shape with the bottom opening 35' therein being disposed concentrically with the small bell hopper 20. Thus, the trackway 32 is positioned on one side of the hopper axis and the trackway 33 is positioned on the other side of the hopper axis.

The small bell hopper 20, and its associated small bell 11 are adapted to be rotated as by means of an electric motor indicated in general at 40 which through a worm 41, wormwheel 42 and pinion 43 is adapted to rotate a ring gear 44. The gear 44is carried by a circular flange 45 which projects from the hopper 20, and the arrangement is such that whenever the motor is rotated, the hopper is likewise rotated. The hopper is supported for rotation on rollers 50, is held down 'by rollers 51, and is guided by rollers 52, all of which are spaced at suitable intervals around the periphery of the hopper.

The hopper 20 is rotated during the dumping of each skip load and rotation is at such speed that the hopper makes at least one revolution during the time required for the fastest dumping operation of any of the materials to be fed into the furnace. Thus, in the ordinary operation of a furnace, a load of coke may be dumped in from three to four seconds, whereas a load of ore may require fourteen seconds to unload. Accordingly, if the hopper is rotated at least 20 revolutions per minute, it will make at least one complete revolution during the fastest time required for any dumping operation.

Where provision is made for utilizing two skip cars, one of which is arranged to dump its contents into the receiving hopper at one side of the axis of the rotating small bell hopper, and the other of which is arranged to dump its contents into the receiving hopper at the other side of the axis of the rotating small bell hopper, and Where the receiving hopper is symmetrically formed and the small hopper is rotated in the same direction during the dumping of each carload, I have found that the distribution is different in uniformity, being more regular or level in the case of the car which is dumping in a direction generally opposed to the direction of the rotation of the hopper, and

the end of each dumping operation.

former rotation.

accomplished by providing control equipmentto'reverse the direction of the small bell hopperrotation as a function of the skip car program, so that when either'skip car dumps the load the revolving small bell hopper rotates in the direction opposed to thatof the'material entering said hopper. Thus, as viewed in Fig. 2, the direction of rotation of the hopper would be counterclockwise as shown by the full-line arrow during the dumping of a skip load from a car which is positioned on the track 32, whereas-the direction of rotation would be clockwise as shown by the broken arrow during the dumping operation of a skip car which is positioned upon the track 33.

In Fig. 6 I have shown a wiring diagram for effecting a reversal of direction of rotation of the hopper motor at In this diagram, a source of current supply is indicated at 60, a main switch at 61, a reversing switch at 62, a'motor63 for operating 'the skip hoist cable, a timer at 64, a hopper control switch 65 and a hopper motor 66. The arrangement is such that whenever the reversing switch is-in the solid line position, then the motor 63 is operated, for example, to elevate the car on the trackway 32.

The timer is set to close the switch 65 and thus to close the circuit through the hopper motor 66. The timer is set to start the hopper motor shortly before the skip car reaches its highest elevating movement, whereby the hopper can be brought up to speed before the dumping operation is started.

Upon movement ofthe switch 62 to the dotted line position 62A, then the current is reversed in the field of the motor 63 and of the motor 66, and the timer is again energized to close the switch 65, whereby the hopper motor 66 is rotated in a direction reverse to that of the Thus when the car, for example, on the trackway '33 is in position for dumping, the hopper will be rotating in a direction opposite to that during the dumping of the car on the trackway 32.

(not shown) therein for opening the switch 65 if desired, so as to condition it to close the circuit through the motor 66 at the proper time during the elevation of thesucceeding skip car.

A modification of my invention is shown in Figs. 4 and 5 wherein the hopper is rotated without change in vdirection during the dumping of the cars on the respective trackways, but wherein the principle of obtaining a flow substantially to a sector of the circular opening 35. This opening enables the contents from the car on the trackway 33 to be guided so as to enter the rotating hopper through the opening 85 while moving in a direction generally opposite to that of rotation of the hopper.

An important advantage of the present invention is that the materials dumped from one car are distributed in the same degree of uniformity as those dumped from the other car. A further advantage is that the desired result is accomplished in a simple and expeditious manner, and that the invention may be applied to existing equipment without requiring material changes in the construction thereof. The effect of the present invention is to utilize the combined action of the swirl imparted to the material The closing of the switch 62' energizes the timer 64 through the return conductor 64A.

It is to be. understood that the timer 64 has suitable mechanism complete revolution during the dumping of each carload comprising, causing the materials to enter the rotating hopper from each of said cars in a direction which is generally opposite to the direction of rotation of the hopper.

2. A method of charging a blast furnace according to claim 1, wherein the opposition of material flow to the direction of rotation of the hopper is attained by reversing the direction of rotation of the hopper during the dumping of each succeeding carload.

3. A method according to claim 1, wherein the hopper is always rotated in one direction during the dumping of one car and is always rotated in the opposite direction during the dumping of the other car.

4. A method according to claim 1, wherein the opposition of material flow to the direction of rotation of the hopper is attained by maintaining the'hopper rotation in one direction during allof the dumping operations, but changing the direction of fiow of the material "from one of the cars so that it is caused to enter the rotating hopper at a point which results in opposition of material how to the direction of rotation of the hopper.

5. A method according to claim 1, wherein the opposition of material flow to the direction of rotation of the hopper is attained by guiding the materials flowing from one of the cars so as to reverse its direction of movement at the time of entering the rotating hopper.

6. An apparatus for charging a blast furnace, wherein materials to be fed into the furnace are delivered to the top of it in a pair of cars, and wherein the cars are dumped alternately into a rotating hopper which is closed by a'movable bell comprising in combination, means for rotating the hopper and bell as a unit at least one comhopper.

7. An apparatus for charging a blast furnace, wherein materials to be fed into the furnace are delivered to the 'top of it in a pair of cars and, wherein the cars are alternately dumped into a rotating hopper which is closed by a movable bell, comprising in combination a receiving hopper which is disposed above the rotating hopper and is symmetrically formed with respect to the axis of the hopper, and means for rotating the first mentioned hopper in one direction at least one complete revolution during the dumping operation of one of the cars and rotating the first-mentioned hopper in the opposite direction during the dumping operation of the other of said cars.

8. An apparatus for charging a blast furnace, wherein materials to be fed into the furnace are delivered to the top of it in a pair of cars, and wherein the cars are alternately dumped into a rotating hopper which is closed by a movable bell, comprising in combination an electric motor for rotating the hopper and bell as a unit, a source of current supply, a circuit from the source of supply to said motor, a second motor for operating flie cars, a cir cuit for said second motor to said source of supply and a reversible switch for reversing the direction of rotation of the hopper motor whenever the direction of the car motor rotation is reversed.

9. In a blast furnace having a rotating small bell hopper at the top thereof, an electric motor for rotating the hopper, a pair of skip cars, an electric motor for'actuat ng the cars, a circuit for each of said motors, a timer bone as it flows from the receiving hopper into the bell hopper 79 of said circuits and operable to close the circuit through the hopper motor after the car motor has been in operation for a predetermined length of time, said circuit including means for reversing the hopper motor upon reversal of the car motor.

10. An apparatus for charging a blast furnace, wherein materials to be fed into the furnace are delivered to the top of it in a pair of cars, and wherein the cars are dumped alternately into a rotating hopper which is closed by a movable bell, comprising in combination means for rotating the hopper at least one complete revolution during each dumping operation, the direction of rotation of the hopper being the same during all dumping operations, and means for guiding the material flowing from one of the cars so as to reverse its direction of flow and cause it to enter the hopper in a direction which is generally opposite to the direction of rotation of the hopper.

11. A receiving hopper for a blast furnace having a partition dividing it into two chambers, one of which is adapted to receive the material from one of a pair of skip cars, and the other of which is adapted to receive material from the other of said pair of skip cars, said partition extending substantially in the same general direction as the path of movement of the skip cars one of said chambers having a bottom wall formed to impart a swirl in one direciton to materials entering it from one of the skip cars, and the other of said chambers having a bottom wall 6 formed to elfect a swirl in the same direction to materials entering the receiving hopper from the other of said skip cars.

12. A receiving hopper for a blast furnace, said hopper having a partition dividing it into two material-receiving chambers, one of said chambers being adapted to receive material from one of a pair of skip cars, and the other of said chambers being adapted to receive materials from the other of said pair of skip cars, said partition extending substantially in the same generally direction as the path of movement of the skip cars each of said chambers having an opening in the bottom thereof, the opening in one of the chambers being substantially a quadrant, said lastmentioned chamber having sloping walls to guide the materials entering it in a direction which is reversed to the direction of flow of the materials entering such chamber from the skip car.

References Cited in the file of this patent UNITED STATES PATENTS 336,749 Rotthotf Feb. 23, 1886 816,222 Dougherty Mar. 27, 1906 864,053 Witherbee et al. Aug. 20, 1907 910,264 Baker Jan. 19, 1909 1,033,036 Roberts July 16, 1912 

